Upper segment to lower segment ratio in a 3-year-old child is:
What is the recommended rate for blood transfusion in neonates?
Double aortic arch is associated with which syndrome?
What is the PRIMARY pathophysiological mechanism underlying the most common cause of neonatal hyperbilirubinemia?
Most common site of extramedullary relapse of ALL in a 6-year-old boy is
A 3-month-old infant presents with an abdominal palpable mass and non-bilious vomiting. What is the most likely diagnosis?
Rehydration therapy in a 2 year old severely dehydrated child is -
What is the correct dose of i.v. adrenaline in term infants during neonatal resuscitation?
Rubella is known to cause all of the following conditions except:
An XX baby presenting with male genitalia (penis and scrotum) is likely due to which of the following conditions?
NEET-PG 2012 - Pediatrics NEET-PG Practice Questions and MCQs
Question 31: Upper segment to lower segment ratio in a 3-year-old child is:
- A. 1.2:1
- B. 1.3:1 (Correct Answer)
- C. 1.4:1
- D. 1.6:1
Explanation: ***1.3:1*** - At birth, the upper segment to lower segment ratio is around **1.7:1**, indicating proportionally longer trunks. - By the age of **3 years**, this ratio typically decreases to approximately **1.3:1** as the lower limbs grow more rapidly. *1.2:1* - This ratio is typically observed in **older children** or young adults, as lower limb growth catches up further. - A ratio of 1.2:1 would suggest more **proportional body segments** than expected for a 3-year-old child. *1.4:1* - This ratio is closer to that of a **younger infant** or toddler, as the lower segments are still relatively shorter. - A 3-year-old would generally have experienced more **lower limb growth**, reducing this ratio further. *1.6:1* - This ratio is characteristic of a **newborn or very young infant**, where the upper body and head are significantly larger relative to the legs. - It would be **abnormal** for a 3-year-old to still have such a high ratio, indicating a disproportional growth pattern.
Question 32: What is the recommended rate for blood transfusion in neonates?
- A. 1-5 ml/min (Correct Answer)
- B. 10-15 ml/min
- C. 15-20 ml/min
- D. 5-10 ml/min
Explanation: ***1-5 ml/min*** - The recommended rate for blood transfusion in neonates is **1-5 ml/min** to prevent **circulatory overload** and other complications. - Slower rates are crucial for neonates due to their limited cardiovascular reserves and smaller blood volume. *5-10 ml/min* - This rate is generally **too fast** for routine neonatal blood transfusions, increasing the risk of **fluid overload** and **cardiac strain**. - Rapid administration can lead to complications such as **necrotizing enterocolitis (NEC)** or **respiratory distress**. *10-15 ml/min* - Administering blood at this rate in neonates is **contraindicated** due to the high risk of **cardiovascular compromise**. - It could quickly overwhelm the neonate's circulatory system, leading to severe adverse events. *15-20 ml/min* - This rate is significantly **too rapid** for any neonatal blood transfusion and would almost certainly result in **severe volume overload** and potential cardiac arrest. - Such high rates are only rarely considered in extreme emergency situations, like massive hemorrhage with specific considerations and monitoring.
Question 33: Double aortic arch is associated with which syndrome?
- A. DiGeorge syndrome (Correct Answer)
- B. CATCH 22 syndrome
- C. Shprintzen syndrome
- D. None of the options
Explanation: ***DiGeorge syndrome*** - **DiGeorge syndrome** is caused by a **22q11.2 deletion** affecting the development of the third and fourth pharyngeal pouches, leading to **thymic hypoplasia**, **parathyroid hypoplasia**, and **cardiac anomalies**. - Common cardiac defects include **interrupted aortic arch type B**, **truncus arteriosus**, **tetralogy of Fallot**, and **VSD**. - **Double aortic arch** can occur in 22q11.2 deletion syndrome, though it is less common than other cardiac anomalies; however, among the syndromes listed, this represents the most appropriate association. - The question tests recognition that various cardiac arch anomalies, including double aortic arch, may be seen in this genetic syndrome. *CATCH 22 syndrome* - This is an **acronym** for DiGeorge syndrome: **C**ardiac defects, **A**bnormal facies, **T**hymic hypoplasia, **C**left palate, **H**ypocalcemia, and **22q11 deletion**. - It is **essentially the same condition** as DiGeorge syndrome, just using different nomenclature. - While technically correct, "DiGeorge syndrome" is the more standard medical terminology currently used. *Shprintzen syndrome* - **Shprintzen syndrome** (also called **velocardiofacial syndrome or VCFS**) is caused by the **same 22q11.2 deletion** as DiGeorge syndrome. - It represents a **phenotypic variant within the 22q11.2 deletion syndrome spectrum**, with more emphasis on palatal and facial features. - Since it shares the same genetic basis, it can also present with similar cardiac anomalies, but "DiGeorge syndrome" is the more commonly recognized term for this genetic disorder. *None of the options* - This is incorrect because the three syndromes listed above (DiGeorge, CATCH 22, and Shprintzen) all refer to **22q11.2 deletion syndrome** or its variants, which can be associated with various cardiac anomalies including double aortic arch. - Among the listed options, **DiGeorge syndrome** is the most appropriate and widely recognized answer.
Question 34: What is the PRIMARY pathophysiological mechanism underlying the most common cause of neonatal hyperbilirubinemia?
- A. Inefficient erythropoiesis
- B. Immature liver enzyme (Correct Answer)
- C. RBC hemolysis
- D. Decreased bilirubin excretion
Explanation: ***Immature liver enzyme*** - The most common cause of neonatal hyperbilirubinemia is **physiological jaundice**, and its PRIMARY pathophysiological mechanism is **immature hepatic conjugation** due to deficiency of **UDP-glucuronosyltransferase (UGT1A1)**. - While neonates do produce more bilirubin from RBC breakdown, the **rate-limiting step** is the liver's inability to conjugate unconjugated bilirubin efficiently for excretion. - This immaturity causes accumulation of unconjugated bilirubin, which peaks at **3-5 days of life** and resolves as the enzyme system matures by **7-10 days**. - Key clinical feature: **Unconjugated (indirect) hyperbilirubinemia** in an otherwise healthy term neonate. *RBC hemolysis* - Neonates do have a **shorter RBC lifespan** (70-90 days vs. 120 days in adults) and higher hematocrit, leading to increased bilirubin production (~2-3 times adult rate). - However, this is a **contributory factor**, not the primary mechanism—a normal liver can handle this load easily. - **Pathological hemolysis** (ABO/Rh incompatibility, G6PD deficiency, spherocytosis) causes jaundice through a different mechanism with earlier onset (<24 hours) and more severe hyperbilirubinemia. *Inefficient erythropoiesis* - Ineffective erythropoiesis (abnormal RBC production with intramedullary destruction) is seen in conditions like **thalassemia** and **megaloblastic anemia**. - This can contribute to increased bilirubin load but is not the mechanism in physiological jaundice. - In neonates, erythropoiesis is typically transitioning from fetal to adult hemoglobin but is not pathologically inefficient. *Decreased bilirubin excretion* - Decreased excretion of **conjugated bilirubin** occurs in **cholestatic conditions** (biliary atresia, neonatal hepatitis, choledochal cyst). - This results in **direct (conjugated) hyperbilirubinemia**, not the indirect hyperbilirubinemia seen in physiological jaundice. - While neonates do have relatively decreased enterohepatic circulation clearance, the primary bottleneck is conjugation, not excretion.
Question 35: Most common site of extramedullary relapse of ALL in a 6-year-old boy is
- A. Testes
- B. Liver
- C. CNS (Central Nervous System) (Correct Answer)
- D. Lung
Explanation: ***CNS (Central Nervous System)*** - The **central nervous system** is the **most common site of extramedullary relapse** in pediatric acute lymphoblastic leukemia (ALL), accounting for the majority of extramedullary relapses. - CNS is an immunologically privileged sanctuary site where chemotherapy penetration is limited due to the blood-brain barrier. - CNS relapse presents with symptoms like headache, vomiting, cranial nerve palsies, or signs of increased intracranial pressure and requires intrathecal chemotherapy and cranial irradiation. - Prophylactic CNS therapy is a standard component of ALL treatment protocols to prevent CNS relapse. *Testes* - **Testes** are the **second most common** site of extramedullary relapse and the most common **solid organ** site in boys with ALL. - Like the CNS, testes are immunologically privileged sites with limited chemotherapy penetration. - Testicular relapse presents as painless testicular enlargement (unilateral or bilateral) and requires testicular radiation plus systemic therapy intensification. *Liver* - While **hepatic infiltration** can occur in ALL, the liver is not a common site for **isolated extramedullary relapse**. - Hepatic involvement typically indicates widespread systemic disease rather than a primary relapse site. *Lung* - **Pulmonary involvement** in ALL is rare as an isolated extramedullary relapse site. - Lung findings in ALL patients are more commonly due to infection, leukostasis in hyperleukocytosis, or disseminated disease.
Question 36: A 3-month-old infant presents with an abdominal palpable mass and non-bilious vomiting. What is the most likely diagnosis?
- A. Hypertrophic pyloric stenosis (Correct Answer)
- B. Tracheoesophageal fistula
- C. Duodenal atresia
- D. Intussusception
Explanation: ***Hypertrophic pyloric stenosis*** - The classic presentation includes **projectile non-bilious vomiting** and a palpable **olive-shaped mass** in the epigastrium of an infant typically between 3 weeks and 6 months of age. - The vomiting is non-bilious because the obstruction is proximal to the ampulla of Vater. *Intussusception* - While it can present with an **abdominal mass** and vomiting, the vomiting is often **bilious** and the classic stool is **'currant jelly'**, which is not mentioned here. - It usually presents with sudden onset of severe, **colicky abdominal pain** and occurs more commonly in slightly older infants (6-12 months). *Tracheoesophageal fistula* - This condition presents at birth with symptoms such as **choking, coughing**, and **cyanosis** during feeding. - It usually causes respiratory distress and feeding difficulties from the first days of life, not a palpable abdominal mass and non-bilious vomiting at 3 months. *Duodenal atresia* - This is a congenital obstruction that typically presents with **bilious vomiting** (as the obstruction is distal to the ampulla of Vater) within the first 24-48 hours of life. - Imaging usually shows a **“double bubble” sign** on abdominal X-ray, and an abdominal mass is not typically palpable.
Question 37: Rehydration therapy in a 2 year old severely dehydrated child is -
- A. 75 ml/kg in 4 hours
- B. 30 ml/kg in 1 hour, 70 ml/kg in 5 hours
- C. 20 ml/kg in 30 min, 80 ml/kg in 2.5 hours
- D. 30 ml/kg in 30 min, 70 ml/kg in 2.5 hours (Correct Answer)
Explanation: ***30 ml/kg in 30 min, 70 ml/kg in 2.5 hours*** - This option reflects the recommended rehydration protocol for a severely dehydrated child aged **12 months to 5 years**, where the first 30 ml/kg are given rapidly over 30 minutes, followed by 70 ml/kg over the next 2.5 hours. - This rapid initial infusion helps to quickly restore **circulating volume** and improve perfusion during severe dehydration. *30 ml/kg in 1 hour, 70 ml/kg in 5 hours* - This protocol is typically used for children with **some dehydration**, not severe dehydration, and is usually administered orally when possible. - The slower rate of rehydration would be insufficient for a severely dehydrated child requiring more urgent fluid replacement. *20 ml/kg in 30 min, 80 ml/kg in 2.5 hours* - While reflecting a rapid initial phase, the total volume and distribution of fluids differ from the WHO guidelines for **severe dehydration** in this age group. - The **initial 20 ml/kg over 30 minutes** is generally a slightly lower first bolus than recommended for very severe cases, and the subsequent phase is also adjusted. *75 ml/kg in 4 hours* - This represents a **lower total volume** (75 ml/kg compared to 100 ml/kg) and a different time distribution for severely dehydrated children in the 12 month to 5 year age group. - This protocol is more aligned with the management of **some dehydration** rather than the urgent requirements of severe dehydration.
Question 38: What is the correct dose of i.v. adrenaline in term infants during neonatal resuscitation?
- A. 0.1-0.3 ml/kg in 1:10,000 (Correct Answer)
- B. 0.03-0.05 ml/kg in 1:1,000
- C. 0.01-0.03 ml/kg in 1:1,000
- D. 0.3-0.5 ml/kg in 1:10,000
Explanation: ***0.1-0.3 ml/kg in 1:10,000*** - The recommended intravenous adrenaline dose for neonatal resuscitation is **0.01-0.03 mg/kg** using a **1:10,000 solution (0.1 mg/mL)**. - Volume calculation: 0.01-0.03 mg/kg ÷ 0.1 mg/mL = **0.1-0.3 mL/kg**. - This is the standard dose as per **NRP (Neonatal Resuscitation Program)** and **AHA guidelines** [2]. - The 1:10,000 concentration is safer for IV/umbilical venous catheter administration in neonates. *0.01-0.03 ml/kg in 1:1,000* - This volume is far too low for a 1:1,000 solution. - Would deliver only 0.01-0.03 mg total (not per kg), resulting in a **sub-therapeutic dose**. - The 1:1,000 concentration contains 1 mg/mL, which is **10 times more concentrated** than the recommended dilution. *0.3-0.5 ml/kg in 1:10,000* - This volume would deliver 0.03-0.05 mg/kg, which **exceeds the recommended maximum** of 0.03 mg/kg. - Higher doses can cause **severe adverse effects** including hypertension, arrhythmias, decreased myocardial function, and compromised coronary perfusion. - Not recommended as the standard initial dose. *0.03-0.05 ml/kg in 1:1,000* - The 1:1,000 concentration (1 mg/mL) is **too concentrated for IV use** in neonates [1]. - This volume would deliver 0.03-0.05 mg/kg from a highly concentrated solution, increasing risk of **severe cardiovascular complications**. - The 1:1,000 solution is reserved for **endotracheal administration** (at higher volumes of 0.5-1 mL/kg), not IV route.
Question 39: Rubella is known to cause all of the following conditions except:
- A. Conduction defects
- B. VSD
- C. Microcephaly
- D. Glaucoma (Correct Answer)
Explanation: ***Glaucoma*** - While rubella can cause **ocular defects** such as **cataracts** and **pigmentary retinopathy**, glaucoma is not a typical congenital manifestation of rubella syndrome. - **Congenital glaucoma** is more commonly associated with other genetic syndromes or developmental anomalies. *Microcephaly* - **Microcephaly** is a recognized neurological complication of congenital rubella syndrome, resulting from impaired brain development due to viral infection. - The rubella virus can interfere with the **proliferation and migration** of neuronal cells during fetal development. *VSD* - **Ventricular septal defect (VSD)** is a common congenital heart defect associated with congenital rubella syndrome. - Other cardiac anomalies seen include **patent ductus arteriosus (PDA)** and **pulmonary artery stenosis**. *Conduction defects* - **Conduction defects** and other **cardiac arrhythmias** can occur in congenital rubella syndrome due to direct viral damage to the developing cardiac conduction system. - This can manifest as **bradyarrhythmias** or various degrees of **heart block**.
Question 40: An XX baby presenting with male genitalia (penis and scrotum) is likely due to which of the following conditions?
- A. Turner syndrome
- B. None of the options
- C. Klinefelter syndrome
- D. High level of testosterone in maternal blood (Correct Answer)
Explanation: ***High level of testosterone in maternal blood*** - An **XX baby** (genetically female) presenting with **fully masculinized external genitalia** (penis and scrotum) indicates significant **androgen exposure** during the critical period of sexual differentiation (8-12 weeks of gestation). - While the most common cause is **congenital adrenal hyperplasia (CAH)** due to fetal androgen excess, **maternal sources of androgens** can also cause complete masculinization. - Maternal causes include **virilizing tumors** (e.g., luteoma of pregnancy, Krukenberg tumor, arrhenoblastoma), **exogenous androgen administration**, or **maternal CAH**. - High sustained maternal testosterone crosses the placenta and causes **virilization of female fetus**, which can range from clitoromegaly to complete male phenotype. - This is the **only medically correct option** among the choices given, though CAH (not listed) would be the most common cause overall. *Klinefelter syndrome* - **47, XXY karyotype** - genetically male due to presence of Y chromosome with SRY gene. - Presents as phenotypic male, not relevant to an **XX individual**. - Features include hypogonadism, infertility, tall stature, and gynecomastia. *Turner syndrome* - **45, X karyotype** - monosomy X, genetically and phenotypically female. - Presents with **female external genitalia**, streak gonads, short stature, webbed neck. - Cannot explain masculinized genitalia in any scenario. *None of the options* - This is incorrect because **high level of testosterone in maternal blood** is a documented cause of XX virilization with male phenotype, though less common than fetal CAH.